// HTMLParser Library - A java-based parser for HTML
// http://htmlparser.org
// Copyright (C) 2006 Derrick Oswald
//
// Revision Control Information
//
// $URL: https://svn.sourceforge.net/svnroot/htmlparser/trunk/filterbuilder/src/main/java/org/htmlparser/parserapplications/filterbuilder/wrappers/TagNameFilterWrapper.java $
// $Author: derrickoswald $
// $Date: 2006-09-16 10:44:17 -0400 (Sat, 16 Sep 2006) $
// $Revision: 4 $
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the Common Public License; either
// version 1.0 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// Common Public License for more details.
//
// You should have received a copy of the Common Public License
// along with this library; if not, the license is available from
// the Open Source Initiative (OSI) website:
//   http://opensource.org/licenses/cpl1.0.php

package org.htmlparser.parserapplications.filterbuilder.wrappers;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import javax.swing.JComboBox;

import org.htmlparser.Node;
import org.htmlparser.NodeFilter;
import org.htmlparser.Parser;
import org.htmlparser.Tag;
import org.htmlparser.filters.TagNameFilter;
import org.htmlparser.parserapplications.filterbuilder.Filter;
import org.htmlparser.tags.CompositeTag;
import org.htmlparser.util.NodeIterator;
import org.htmlparser.util.NodeList;
import org.htmlparser.util.ParserException;

/**
 * Wrapper for TagNameFilters.
 */
public class TagNameFilterWrapper extends Filter implements ActionListener {
	/**
	 * The underlying filter.
	 */
	protected TagNameFilter mFilter;

	/**
	 * Combo box for tag name.
	 */
	protected JComboBox mName;

	/**
	 * Create a wrapper over a new TagNameFilter.
	 */
	public TagNameFilterWrapper() {
		mFilter = new TagNameFilter();

		// add the tag name choice
		mName = new JComboBox();
		mName.setEditable(true);
		add(mName);
		mName.addItem(mFilter.getName());
		mName.addActionListener(this);
	}

	//
	// Filter overrides and concrete implementations
	//

	/**
	 * Get the name of the filter.
	 * 
	 * @return A descriptive name for the filter.
	 */
	public String getDescription() {
		return ("Tag named");
	}

	/**
	 * Get the resource name for the icon.
	 * 
	 * @return The icon resource specification.
	 */
	public String getIconSpec() {
		return ("images/TagNameFilter.gif");
	}

	/**
	 * Get the underlying node filter object.
	 * 
	 * @return The node filter object suitable for serialization.
	 */
	public NodeFilter getNodeFilter() {
		TagNameFilter ret;

		ret = new TagNameFilter();
		ret.setName(mFilter.getName());

		return (ret);
	}

	/**
	 * Assign the underlying node filter for this wrapper.
	 * 
	 * @param filter
	 *            The filter to wrap.
	 * @param context
	 *            The parser to use for conditioning this filter. Some filters
	 *            need contextual information to provide to the user, i.e. for
	 *            tag names or attribute names or values, so the Parser context
	 *            is provided.
	 */
	public void setNodeFilter(NodeFilter filter, Parser context) {
		Set set;

		mFilter = (TagNameFilter) filter;
		set = new HashSet();
		context.reset();
		try {
			for (NodeIterator iterator = context.elements(); iterator.hasMoreNodes();)
				addName(set, iterator.nextNode());
		} catch (ParserException pe) {
			// oh well, we tried
		}
		for (Iterator iterator = set.iterator(); iterator.hasNext();)
			mName.addItem(iterator.next());
		mName.setSelectedItem(mFilter.getName());
	}

	/**
	 * Get the underlying node filter's subordinate filters.
	 * 
	 * @return The node filter object's contained filters.
	 */
	public NodeFilter[] getSubNodeFilters() {
		return (new NodeFilter[0]);
	}

	/**
	 * Assign the underlying node filter's subordinate filters.
	 * 
	 * @param filters
	 *            The filters to insert into the underlying node filter.
	 */
	public void setSubNodeFilters(NodeFilter[] filters) {
		// should we complain?
	}

	/**
	 * Convert this filter into Java code. Output whatever text necessary and
	 * return the variable name.
	 * 
	 * @param out
	 *            The output buffer.
	 * @param context
	 *            Three integers as follows:
	 *            <li>indent level - the number of spaces to insert at the
	 *            beginning of each line</li>
	 *            <li>filter number - the next available filter number</li>
	 *            <li>filter array number - the next available array of filters
	 *            number</li>
	 * @return The variable name to use when referencing this filter (usually
	 *         "filter" + context[1]++)
	 */
	public String toJavaCode(StringBuffer out, int[] context) {
		String ret;

		ret = "filter" + context[1]++;
		spaces(out, context[0]);
		out.append("TagNameFilter ");
		out.append(ret);
		out.append(" = new TagNameFilter ();");
		newline(out);
		spaces(out, context[0]);
		out.append(ret);
		out.append(".setName (\"");
		out.append(mFilter.getName());
		out.append("\");");
		newline(out);

		return (ret);
	}

	/**
	 * Add the tag name and it's children's tag names to the set of tag names.
	 * 
	 * @param set
	 *            The set to add to.
	 * @param node
	 *            The node to get the names from.
	 */
	protected void addName(Set set, Node node) {
		NodeList children;

		if (node instanceof Tag) {
			set.add(((Tag) node).getTagName());
			if (node instanceof CompositeTag) {
				children = ((CompositeTag) node).getChildren();
				if (null != children)
					for (int i = 0; i < children.size(); i++)
						addName(set, children.elementAt(i));
			}
		}
	}

	//
	// NodeFilter interface
	//

	/**
	 * Predicate to determine whether or not to keep the given node. The
	 * behaviour based on this outcome is determined by the context in which it
	 * is called. It may lead to the node being added to a list or printed out.
	 * See the calling routine for details.
	 * 
	 * @return <code>true</code> if the node is to be kept, <code>false</code>
	 *         if it is to be discarded.
	 * @param node
	 *            The node to test.
	 */
	public boolean accept(Node node) {
		return (mFilter.accept(node));
	}

	//
	// ActionListener interface
	//

	/**
	 * Invoked when an action occurs on the combo box.
	 * 
	 * @param event
	 *            Details about the action event.
	 */
	public void actionPerformed(ActionEvent event) {
		Object source;
		Object[] selection;

		source = event.getSource();
		if (source == mName) {
			selection = mName.getSelectedObjects();
			if ((null != selection) && (0 != selection.length))
				mFilter.setName((String) selection[0]);
		}
	}
}
